In fast-food restaurants and similar such establishments, beverages at present are normally served in a round container having a conically upwards and outwards sloping side wall and typically such containers are used with loose lids that can be fitted over the upper rim of the container. The lid typically is provided with a weakening in the center or other position of the lid through which a drinking straw can be pushed for consuming the contents of the container without the need to remove the lid.
Such containers have numerous drawbacks in that the use of a lid which caps such a container is not effective in preventing the beverage from leaking from the container during use and particularly if the container were to be upset. Such occurs because the container has a relatively thin wall which is easily deformed when it is upset and the lid will loosen causing the contents of the container to be dispensed even though such is not desired.
To overcome such problems existing in the typical prior art disposable containers, a self-sealing portable container was sought after. Various types of structures have been disclosed such, for example, as that shown in U.S. Pat. No. 5,358,175, which is a container formed of a foldable sheet material which requires assembly, interconnection of flaps and a tongue-slot combination. U.S. Pat. No. 4,850,528 discloses a self-locking, self-closing container using a spring-action pleated top. U.S. Pat. No. 5,676,306 discloses a container having a sealing top formed by a series of crease lines folding inwardly and forming a series of rectangles, each having a diagonal corner portion to form a closure panel. U.S. Pat. No. 4,135,512 discloses a container having an integral flat lid hinged to a cylindrical wall. The lid extends in a downward slope and locks in a closed position between two ridges formed in opposite sides of the wall. The lid contains a plurality of openings therein so that liquid contained in the container can pass through the closed lid along with medication held on top of the lid. The most pertinent prior art known to applicant is that shown in U.S. Pat. Nos. 5,960,987 and 6,164,488. These two patents disclose a container having an integral lid hinged about the wall of the container to selectively close and seal the same on demand. The integral lid is formed by a crease within the wall of the container and the crease defines the bottom end of the lid. The lid's top end is arcuate and extends above the top portion of the cup. The user can then move the lid to a closed position so that it engages a ridge causing the lid to conform to the shape of the top portion of the cup with the lid extending generally upwardly with the lid defining an aperture through which the contents of the container may be dispensed. Although devices of this type do function somewhat effectively, it has been found that the leakage around the lid is such that the utility of the package is somewhat limited and creates undesirable spillage of the contents during attempted use of the container.
There is thus a need for a simple self-sealing container utilizing an integral lid which accomplishes a positive and effective seal when the lid is closed so that leakage from the container is eliminated during normal use thereof.